Transmissions through multi-path channels usually experience inter-symbol interference at a receiver. One of the methods to mitigate the interference is to utilise an equalizer at the receiver to compensate for channel distortion.
Iterative turbo methods have been used for channel equalization where a channel equalizer and a channel decoder exchange information iteratively. One of the methods consists of a soft interference canceller followed by a Minimum mean-square error MMSE filter (SC/MMSE) optimised with the channel decoder feedback, channel response and noise level.
The dominating computational complexity of the SC/MMSE algorithm lies in the computation of the inverse of the interference covariance matrix. The inverse is calculated for each transmitted symbol in the received signal.